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December 10, 2010


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Hooray. Having worked in my twenties for six years in an azalea rhododendron production nursery I now realize that I have unwittingly acquired an elevated risk of dying of asbestosis (or from getting lung cancer from asbestos fibers in vermiculite)..........

Krubozumo Nyankoye

This is one that is hard to resist.

I can't tell from the photograph alone but I think as mentioned in oddjob's comment that the stuff looks like vermiculite. I am a geologist and I have no idea what Zonolite is, unless that is some brand name.

However, I have to take some exception to what oddjob says and what is implied in the OP, vermiculate and asbestos (in several chemical varieties) might have coincidental relationships and space but are chemically discrete.

Though undoubtedly there may be trace amounts of asbestosform minerals present in an industrially produced mineral such as vermiculite it is unlikely that they would exist in significant proportions simply because if they did their properties are so different that the functional pupose of the vermiculite product would be compromised and sub-standard. Moreover, the environments in which the two minerals occur are sufficiently different that accidental inclusion of asbestos minerals in mine product is unlikely.

I have not read the linked article admittedly, however, I would point out that a very common use of vermiculite is as cat litter, and as such would pose a much higher risk than attic insulation if I infer correctly from the bits I have gleaned from this post and oddjob's comment.

While it may well be true that it would be a good idea to remove vermiculite attic insulation from one's home if one can afford to do so, I think that the in the broader context, the EPA should be more concerned with greenhouse gas emissions.

In point of fact, it would not surprise me in the least if this publicity over asbestos in insulation was a campaign designed by carbon polluters to discredit the EPA.

I should respond to oddjob more directly as well. While it may be true that your risk of some discrete diseases was slightly increased by exposing yourself to vermiculite at some time for some period in the past, statistically your increased risk is vanishingly small. So small it would be difficult to calculate the level of increased risk with statistical significance. By contrast your statistical risk of death from driving to and from work is probably a few orders of magnitude greater. As would be any number of other activities which we all take for granted, such as riding a bicycle, or taking a shower, or cleaning the oven. Life is full of risks, some we know, some we don't know.

I do not mean to discredit the idea that we should strive to organize society in a responsible way. On the contrary, I am much in favor of that very thing, but I think that aiming at minute problems such as this, tends to trivialize the whole process, and in fact give ammunition to those who favor not just lassie faire but anything goes.

kathy a.

well said, KN.


It is vermiculite, with a commercial brand name, without doubt.

KN, I'm a horticulturist and entomologist, not a geologist (beyond "interested layman" status) and so I'd be very interested in reading what you had to say after you've read the link and the related EPA info. as it applies to professional horticulturists & landscapers, bearing in mind that I was working with a W. R. Grace vermiculite product back in the 1980's when they were mining this stuff from that locale in Montana, and it at the time was apparently 70% of the vermiculite available for sale in the USA.

Fortunately I did other work than mix the nursery's potting mix, but I certainly did plenty of that work when it needed to be done. In the summer, when the heaviest amount of that work was taking place I was busy taking azalea cuttings for the next year's crop, but in the autumn, when the high school students were gone, I was absolutely very involved with potting up next year's product. I also was often one of those involved with offloading the bags of vermiculite into the barn when we received the annual delivery of vermiculite from Grace. We'd get most of a tractor trailer load of the large bags of it, and move it off the tractor trailer into the old barn on the property.


I think that the in the broader context, the EPA should be more concerned with greenhouse gas emissions.

None of what I've just written should be construed as though I disagree with this!

Lisa Simeone

Quoting: "asbestos-laden vermiculite."

The opposition to the warning, they said, came from two senior political appointees and some "old-timers" from EPA's Office of Pollution Prevention and Toxics who knew that in 1982 the EPA first learned of the danger of vermiculite mined in the tiny northwest Montana town of Libby and did nothing.

"We were told that if the agency said nothing in reaction to recent news reports of the dangers, the issue of the Zonolite warning would just fade again as it has every time it was raised in the past," said an agency lawyer who read many of the e-mails between senior people weighing the language in a statement.

As for whether it's more important than, less important than, as important as, sort of as important as, not anywhere near as important as emissions or anything else the EPA has jurisdiction over, I have no idea and don't claim to. Whether it's "a campaign designed by carbon polluters to discredit the EPA," I certainly don't know. I thought it was an interesting story, I'd never heard of Zonolite before, I was only aware of asbestos as asbestos, and I thought others might be interested as well. I don't have any ulterior motives. C'est tout.

Krubozumo Nyankoye

Lisa, I didn't mean or intend to imply any ulterior motives on your part at all, or even for that matter to the AOL article/s which I have now read.

Herewith two links:

that appear to address the general issues reasonably well in lay terms but unfortunately do not provide significant resources of a reliably scientific nature. Still both are better than the AOL articles. From those links it appears to me that the EPA has been anything but neglectful concerning W.R. Grace, Libby, MT. or the health related issues of asbestosform minerals in industrial use. Indeed, some former officials of Grace were prosecuted and apparently acquitted. I wonder why that was omitted from the AOL reports.

Oddjob, it sounds to me as if you have some grounds for concern because it seems unlikely that in handling vermiculite back in the 1980s you would have worn particulate inhalent protection and therefore might have had significant exposure. I hope you have no noticable ill effects let alone a positive diagnosis of any related disease but if you do, there appears to be on-going litigation which you might consider joining. It is a very regrettable thing when people are unknowingly involved in risks through their employment.

My overall point here is/was that vermiculite per se is not the villian in these instances, rather it is contamination by (in the MT. case) tremolite which is the magnesian end-member of the tremolite-actinolite solid solution series of amphiboles. Taking it slightly further I would point out that Libby, MT. is certainly the main victim in this instance in so far as Grace would have processed its vermiculite product there to remove as much tremolite as possible in order to give the product optimal characteristics. The tremolite laden waste products of such processing would undoubtedly be hazardous.

In my opinion it is very unlikely that Grace or any other company for that matter, would have processed vermiculite at "hundreds of sites" since that would be very cost intensive, rather I think there may be hundreds of sites where bulk vermiculite was packaged for local delivery but that would hardly have involved the "purification" and "exfoliation" of that bulk material as both of those require specialized large scale equipment.

I guess my larger point is this, although the AOL articles appear to be generally accurate they imply that all vermiculite is hazardous which is simply not the case, and moreover raise the spectre of "deadly dust" being present in millions of homes across the nation without really making a legitimate case for that. Even if the Grace brand name zonolite vermiculite is present in the attics of millions of homes the risk it poses is almost certainly vanishingly small.

So far as I can tell, the EPA has within the contraints of the objections by "political appointees" taken the proper steps respecting informing the public of the hazard in this case and how it can be properly mitigated. If there is a villian in this story it is surely W.R. Grace and not the EPA.

I am reminded somewhat of the great Radon scare back in the 1980s. Sufficiently high concentrations of Radon can certainly be hazardous over long term exposure. Millions of house holds paid nominal amounts on the order of about $20 to "self-test" for Radon gas. I admit to having done so myself though with a somewhat skeptical slant. I did a kind of clandestine experiment of my own, using a dozen Radon test kits four each from three different sources, I exposed them in different environments including placing each in proximity to a small piece of a mineral called Britholite which happens to be also of the mica group but contains very high concentrations of Thorium. It is not quite as radioactive as Radium. All of the test results save one were negative. The one that was positive had been placed in the attic of my house. So the thought then occured to me... pet rock?

I admit, this is an awkward thing to argue. Very often a subtle threat under current circumstances actually has very serious long term implications, equally if not more often it has hardly any at all. In part at least, it is both the purpose and duty of science to try to discriminate between those two types of threat. That is why I brought up the fact that there is a concerted effort on the part of large scale carbon polluters and those who sell polluting necessities like gasoline, to discredit the science behind the alarming potential of the long term threat.

To both Lisa and oddjob I have to say I never intended my comments to be an accusation of any kind against either of you, what I wanted to do was rather enlighten everyone to the fact of the weakness of the overall proposition that vermiculate per se is some kind of threat to health and well being.

If I offended in any way, you have my most sincere apology for doing so. Please see my latest comment hereafter in response to SC's challenge post.

Krubozumo Nyankoye

For some reason I seem to have a subliminal tendency to substitute a for i when spelling vermicul*i*te. I plead guilty by reason of age and infirmity. (not to mention that my typing teacher in 8th grade was a tyrant).

Also, please note, I have changed my response email address for purposes of securing my anonymity such as it is.

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